Early in His ministry, Jesus delivers what we commonly call the Sermon on the Mount (Matthew 5-7). Along with other teachings, Jesus warns against spiritual enemies who use tricks and lies. “Beware of false prophets, who come to you in sheep’s clothing but inwardly are ravenous wolves” (Matthew 7:15). Jesus further warns of the effect of deception. “Many” who expect to be saved will be condemned “on that day” when Jesus returns and pronounces judgment.
Not everyone who says to me, “Lord, Lord,” will enter the kingdom of heaven, but the one who does the will of My Father who is in heaven. On that day many will say to Me, “Lord, Lord, did we not prophesy in Your name, and cast out demons in Your name, and do many mighty works in Your name?” And then will I declare to them, “I never knew you; depart from Me, you workers of lawlessness” (Matthew 7:21-23).
Notice the depth of deception. These are people—many people—whom Jesus has never known. That is to say, He never had a relationship with them. Yet they call on Jesus as Lord. They claim to have done “many mighty works” for Jesus. Now they stand before Jesus as the Judge. They see Jesus in all His glory—including His power to read hearts—yet they boldly insist that Jesus should welcome them. They believe that they have good reasons to be accepted: Look at how we called on Your name! Look at all we have done in Your name! But they have been completely deluded. Jesus has never known them. They had not even started a relationship with Him or entered the kingdom—for entry to the kingdom is the subject of Matthew 7:21. How could they be so completely deceived?
In the context of Matthew 7, Jesus is showing why we must “beware of false prophets.” The term “prophets” refers to people who claim to speak for God. They disguise themselves with “sheep’s clothing” that makes them seem harmless, even attractive. Yet the hidden reality is that they are “ravenous wolves” (Matthew 7:15). They deceive and destroy so effectively that “many” are completely fooled, thinking they are using Christian powers, only to be rejected by Jesus. This is the background, given by Jesus Himself, that helps us to understand other warnings and commands in the New Testament.